Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron, copper, silver, tin, lead and zinc. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon, such as carbon monoxide from incomplete combustion of coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures, as the chemical potential energy of the bonds in carbon dioxide is lower than that of the bonds in the ore.
Polychlorinated biphenyls (PCBs) are organochlorine compounds with the formula C12H10−xClx; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids for electrical equipment. They are highly toxic and carcinogenic chemical compounds, formerly used in industrial and consumer electronic products, whose production was banned internationally by the Stockholm Convention on Persistent Organic Pollutants in 2001.
Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment.
Environmental remediation is the cleanup of hazardous substances dealing with the removal, treatment and containment of pollution or contaminants from environmental media such as soil, groundwater, sediment. Remediation may be required by regulations before development of land revitalization projects. Developers who agree to voluntary cleanup may be offered incentives under state or municipal programs like New York State's Brownfield Cleanup Program. If remediation is done by removal the waste materials are simply transported off-site for disposal at another location. The waste material can also be contained by physical barriers like slurry walls. The use of slurry walls is well-established in the construction industry. The application of (low) pressure grouting, used to mitigate soil liquefaction risks in San Francisco and other earthquake zones, has achieved mixed results in field tests to create barriers, and site-specific results depend upon many variable conditions that can greatly impact outcomes.
Copper extraction refers to the methods used to obtain copper from its ores. The conversion of copper ores consists of a series of physical, chemical, and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations, and other factors.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.
Pyrometallurgy is a branch of extractive metallurgy. It consists of the thermal treatment of minerals and metallurgical ores and concentrates to bring about physical and chemical transformations in the materials to enable recovery of valuable metals. Pyrometallurgical treatment may produce products able to be sold such as pure metals, or intermediate compounds or alloys, suitable as feed for further processing. Examples of elements extracted by pyrometallurgical processes include the oxides of less reactive elements like iron, copper, zinc, chromium, tin, and manganese.
Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs. While once widely used commercially, PBBs are now controlled substances under the Restriction of Hazardous Substances Directive, which limits their use in electrical and electronic products sold in the EU.
Chemetco was formerly one of the largest United States refiners of copper from recycled or residual sources.
This timeline of the 2007 pet food recalls documents how events related to the 2007 pet food recalls unfolded. Several contaminated Chinese vegetable proteins were used by pet food makers in North America, Europe and South Africa, leading to kidney failure in animals fed the contaminated food. Both the centralization of the pet food industry and the speed and manner of the industry and government response became the subjects of critical discussion.
In China, the adulteration and contamination of several food and feed ingredients with inexpensive melamine and other compounds, such as cyanuric acid, ammeline and ammelide, are common practice. These adulterants can be used to inflate the apparent protein content of products, so that inexpensive ingredients can pass for more expensive, concentrated proteins. Melamine by itself has not been thought to be very toxic to animals or humans except possibly in very high concentrations, but the combination of melamine and cyanuric acid has been implicated in kidney failure. Reports that cyanuric acid may be an independently and potentially widely used adulterant in China have heightened concerns for both animal and human health.
Ractopamine is an animal feed additive used to promote leanness and increase food conversion efficiency in farmed animals in several countries, but banned in others. Pharmacologically, it is a phenol-based TAAR1 agonist and β adrenoreceptor agonist that stimulates β1 and β2 adrenergic receptors. It is most commonly administered to animals for meat production as ractopamine hydrochloride. It is the active ingredient in products marketed in the US as Paylean for swine, Optaflexx for cattle, and Topmax for turkeys. It was developed by Elanco Animal Health, a former division of Eli Lilly and Company.
The Dioxin affair was a political crisis that struck in Belgium during the spring of 1999. Contamination of feedstock with polychlorinated biphenyls (PCB) was detected in animal food products, mainly eggs and chickens. Although health inspectors reported the problem in January, measurements were taken only from May 1999 when the media revealed the case. The then Flemish Liberals and Democrats (VLD) opposition leader Guy Verhofstadt claimed that the government was trying to cover up the so-called "nota Destickere", which proved that several secretaries of state were informed much earlier that the food contained PCBs and dioxins.
The Irish pork crisis of 2008 was a dioxin contamination incident in Ireland that led to an international recall of pork products from Ireland produced between September and early December of that year. It was disclosed in early December 2008 that contaminated animal feed supplied by one Irish manufacturer to thirty-seven beef farms and nine pig farms across Republic of Ireland, and eight beef farms and one dairy farm in Northern Ireland, had caused the contamination of pork with between 80 and 200 times the EU's recommended limit for dioxins and dioxin-like PCBs i.e. 0.2 ng/g TEQ fat. The Food Safety Authority of Ireland moved on 6 December to recall from the market all Irish pork products dating from 1 September 2008 to that date. The contaminated feed that was supplied to forty-five beef farms across the island was judged to have caused no significant public health risk, accordingly no recall of beef was ordered. Also affected was a dairy farm in Northern Ireland; some milk supplies were withdrawn from circulation. Processors refused to resume slaughter of pigs until they received financial compensation.
Dioxins and dioxin-like compounds (DLCs) are a group of chemical compounds that are persistent organic pollutants (POPs) in the environment. They are mostly by-products of burning or various industrial processes or, in the case of dioxin-like PCBs and PBBs, unwanted minor components of intentionally produced mixtures.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a polychlorinated dibenzo-p-dioxin (sometimes shortened, though inaccurately, to simply 'dioxin') with the chemical formula C12H4Cl4O2. Pure TCDD is a colorless solid with no distinguishable odor at room temperature. It is usually formed as an unwanted product in burning processes of organic materials or as a side product in organic synthesis.
Solvay Indupa is an Argentine petrochemical company formerly owned by Solvay. It was considering selling this business to Braskem, but the project was rejected by the Brazilian competition authority. Solvay Indupa is one of the largest petrochemical companies in Latin America. The company is headquartered in Buenos Aires and has a Brazilian office located in São Paulo.
Cobalt extraction refers to the techniques used to extract cobalt from its ores and other compound ores. Several methods exist for the separation of cobalt from copper and nickel. They depend on the concentration of cobalt and the exact composition of the ore used.
In 2013, a wide-scale recall of products sold by dairy producer Fonterra was announced after suspected botulism-causing bacteria were found during safety tests. The contaminated whey products had been sold to third parties who use it to produce infant formula and sports drinks. Approximately 1,000 tonnes of consumer product was affected by the recall across seven countries, but no cases of sickened consumers were reported. China, which imports most of its powdered milk from New Zealand, instituted a temporary ban on the import of the ingredient from New Zealand.
